The article argues the absence of an unambiguous correlation between the substantive endings -a/-ya, -o/-ye, Ø (zero) and gender. The analysis of lexical, morphological, word-formation, and phonetic features of nouns identified eight patterns of their distribution by gender, or eight gender-determining facts. They are as follows: 1) lexical dependence of gender (papa (dad) – doch’ (daughter)); 2) lexico-syntactic (umnitsa (that’s my girl/boy); sud’ya (judge); tezka (namesake)); 3) morphological (rulevoi (helmsman) – mostovaya (roadway) – budushchee (future)); 4) phonetic-morphological (sad (garden), geroy (hero)); 5) lexico-morphological (zima (winter), belka (squirrel); sushchestvo (creature), pole (field); 6) word-formation (usilitel’ (intensifier) – yarkost’ (brightness)); 7) coordination (myslishka (little thought) – volchishka (little wolf), pis’mishko (short letter) – domishko (small house)); 8) traditional (pen’ (stump) – ten’ (shadow), nozh (knife) – rozh’ (rye)). The few exceptions to the second and fifth patterns either have to be memorised or fall under another gender-determining rule. The identified patterns of noun distribution by gender must be taken into account when studying the lexico-grammatical category of gender in lessons of Russian as the official language.